Quantum Surf Physics
Scientific Surfboard Design Study
Donn Ito
by
Catch a Wave
Catching a wave, especially your first, is an exhilarating and memorable experience. The feeling is euphoric. You speed on the ocean, as wind rejuvenates your body and spirit. Vision blurs and time seemingly fades as you glide across shimmering water.
Accelerating down sloping wave's face you do not consider the possibility of your thrill ending in a spill. Unfortunately, elements of danger and defeat are synonymous with most sports. Surfing also has its dangers.
Introduction
This is dedicated to Mark Foo, who made great contributions to surfing. He lost his life, pursuing his passion, in a surfing accident at Mavericks, California. Mark's death led to a discovery that can save many other surfers.
Epiphany
Mark Foo left us long before the introduction of inflatable life-saving devices and jet ski support. Inflatable vests were developed after near-death experiences. Before surfers partnered with skilled jet ski rescue drivers, a surfer in distress was on his own. These safety precautions were introduced after many near-drowning experiences.
Fellow legendary surfer Brock Little studied videos of Mark's ride and said, "He hit something". Mark fell after the underside of his surfboard nose, impacted the wave in a very steep drop. Nose lift (rocker) creates a bend in the surfboard bottom. At high speed, an abrupt impact on the bend can launch a skilled surfer. The underside of the bend is called a bow in boats. The boat bow is what impacts water in rough seas. Henceforth the realization: A surfboard may ride through a shallow dive if its bow is not flat and rocker bend is not severe. Note the nose rocker curve Mark utilized in the photo below.
The extreme nose bend keeps the tip out of water, but: exposes the underside to impact in a dive. This design functions well if the nose completely clears water. Alternatively, a high bend combined with a contoured bottom, deflects water and pushes it aside. It reduces hydrodynamic lift or the push back resistance accompanying a hard impact. A lower aspect nose profile may also accomplish this. In the photo below, water is deflected at lower speed and has time to move out of the rider's path. At higher speeds water cannot move and blocks movement. The arrow points out water resistance. Light refraction distorts the surfboard.
Surfboards are designed maximize lift by flattening its entire underside. As nose rocker and speed increases, hydrodynamic lift pushes the board back. Mark's accident brought awareness of the need to reduce hydrodynamic lift in a high-speed dive. Reducing nose rocker and or contouring the nose underside cushions impact with water. It allows the surfboard to keep moving as opposed to abruptly stopping. This change in design can reduce wipeouts caused by pearl diving or nose pokes. Recovery from a shallow dive is possible, not all can be saved. A steep dive or high free fall will stop any surfboard.
With a Final Breath
Mark Foo loved the ocean and the surfing lifestyle; his quotes expressed his love and commitment: "Surfing and Martial Arts are really similar. If you're into it, it's a way of living, a lifestyle. You live it; you don't just do it. My life is surfing." Surfing was Mark’s life as well as his career. He produced a TV series dedicated to surfing called H3O, his acronym for heavy water. Ironically, heavy water may have attributed to his demise. Science can prove that cold water is denser, heavier, and thicker than warm. A surfboard does not move through cold water as easily as warm. This difference is not significant at low speed, however; at high speed, the temperature may be a factor. Coldwater also affects the human body by restricting movement, making breathing difficult and slowing circulation. Thus, cold water is more dangerous than warm Hawaiian water.
On December 23, 1994, Mark got off a flight in San Francisco, from Honolulu. He went directly to a very dangerous surfing spot known as Mavericks. The waves were beautiful, not exceptionally large, but deceptively inviting. Videos show Mark smiling as he entered the water, not knowing the dangers that lay ahead. He caught a warm-up wave and the nose underside or bow of his surfboard stuck. Mark successfully rode out of a shallow nose poke and intended to heed its warning by changing boards. When he disappeared, friends assumed he went in to change boards. Mark did not make it to the beach as the bow stuck again on his next wave, this time with a harder impact. He took off and went into a steep dive. The board abruptly decelerated, disrupting Mark's balance. He fought to keep his footing while plunging vertically in a freefall. Mark could not save the inevitable wipeout and was launched through the air, with his final breath.
Mark once said, "The life I've had has been good enough that I can die happily. Surfing's done that; surfing's given me that. So I can accept dying while I'm surfing." No one really knows how Mark drowned. There is speculation that he hit the bottom, but; it is not known when he hit. A bottom collision may have occurred after drowning or possibly led to drowning. An autopsy revealed some plaque buildup in his arteries. In warmer conditions plaque may not be a deadly issue. Blood circulation is restricted in cold temperatures by constricting veins, conserving blood for organs. When veins constrict with an interior build-up, blocked circulation may cause a loss of consciousness. Common dangers can become deadly in cold water.
Mike Parsons, a fellow big wave surfer, caught the wave immediately after Mark’s and wiped out. Mike says he bumped into another surfer while violently churning in the cold icy water. He later realized that he collided with Mark. This confirms that Mark experienced a two-wave hold down, and was likely still alive at their encounter. Mark did not surface, true to another quote that became his epithet, "If you want the ultimate thrill, you've got to be willing to pay the ultimate price." The truth is, using Mark's experience we may avoid paying the ultimate price.
Speed
Speed is an important factor of surfing, contributing excitement and thrills. More importantly, speed generates lift to support a surfboard with a rider on water's surface. A surfboard speeding on water generates support hydrodynamically. Speed stabilizes a surfboard, by generating water resistance. A speeding vessel applies force on water, but; little water moves. Water does not have time to move or displace from under any fast-moving vessel. At very low speed, water can move out of the way or displace, floatation becomes the supporting force, Archimedes Principle. When water cannot move fast enough to displace a vessel, it becomes somewhat impermeable. This characteristic of water provides resistance which supports speeding objects on its surface, Bernoulli's Principle.
Water also supports you in a shallow dive or fall. As you penetrate water in a dive your body pushes the water out of your path. Water pressure against your body is hydrodynamic force or resistance. Your energy is transferred to water in the form of waves. You generate waves, slowing and descending deeper until your energy or speed dissipates. Descent into liquid is only possible, if the medium has time to move out of your way.
Should you fall from a great height, you will impact water with speed. Speed increases with height, increasing impact force. Water will momentarily stop you on its surface. Your body will absorb the impact, before you decelerate and submerge deeper. Falls from heights over 200 feet may cause serious injury. Landing flat with your body open and outstretched, further resists penetration and increases risk of injury.
The same resistance can also stop or suddenly decelerate a speeding surfboard. A surfboard can suddenly impact water's surface, causing a disruption and a spill. The surfboard may also dive to a sudden stop by impacting water on the wave bottom. The resulting spill may eject a surfer into a churning mix of turbulent water. Once engulfed, a surfer is vulnerable to colliding with a sharp reef or his flying surfboard. These spills occur because water resists parting for speeding objects. Thus, creating one of the most dangerous wipe outs known as pearling, pearl diving or nose poking. All are the same.
A nose poke can abruptly stop a speeding surfboard. An abrupt stop catapults a surfer through space with speed and kinetic energy. The surfboard stopped because it impacted impermeable water, which had no time to move. The flat underside of the surfboard's nose bend, known as rocker, creates hydrodynamic resistance. Rocker is similar to the curved boards under grandma's rocking chair or a child's rocking horse. Forward curve keeps the nose out of water and rear curve helps lift the board out of water for maneuvering. High impact with the flat curve underside into unmovable water, abruptly stops movement. The result can be a dangerous wipe out. High nose rocker works if the underside clears without hard impact.
The red area in the above illustration is exposed to high impact with water. The upward curve keeps the tip out of water, however; with high impact on the bent flat surface or red zone, optimizes resistance or lift. This can abruptly stop movement with a push back effect.
Experiments with bottom contours, which reduce hydrodynamic resistance, have reduced abrupt stops and catapulting. Pearling and nose pokes can be reduced by cushioning nose impacts with water. Water parts for more pointed surfaces and cushions around curved or rounded surfaces.
Surfing has evolved to include aerial maneuvers. Flight is accompanied by hard flat landings. On a hard flat impact, a falling surfboard and rider, collides with water that resists parting. This can cause dangerous wipe outs resulting in injuries. The most frequent wipe outs in aerials occur due to flat landings. Nose and tail landings are more successful. When a surfer weights the nose or tail, he increases the force of impact to penetrate water. A skilled surfer can recover and spin the board around, in a reverse landing. A surfboard is a board much like a flat piece of lumber. Flatness maximizes lift or resistance. This resisting force, hydrodynamic resistance or lift, is water which cannot move. A displacement nose underside or bow will part water and push it aside. This will allow the board to progress further and possibly recover.
In closing a review, speed eliminates time needed for water to out of the way of speeding vessels. Water cannot move, therefore upward pressure builds and generates lift to support the speeding vessel. Pressure prevents fast moving flat objects from submerging. Flat surfaces block water with speed. Most of the water in high speed contact with flat surfaces, stays in place and becomes relatively stationary. Speeding objects can then ride on water's surface. Alternatively, bowed, round or Veed surfaces release water pressure. They allow water to move out of the wave to reduce impact. This is what Tom Blake and Duke Kahanamoku used in some of their surfboard designs. Some old designs will work today.
Please send inquiries to Donn Ito ito808@yahoo.com.
